It has been reported that {bis[2-(diphenylphosphino)-ethyl]amine}carbonylchlorohydridoruthenium(II) [Ru-MACHO (registered trademark), hereinafter the same] which is a kind of ruthenium complex exhibits excellent catalytic activity in a hydrogenation reaction of various carbonyl compounds such as ketones, esters and lactones and gives alcohols efficiently (Patent Document 1).
In the production method of this ruthenium complex, as shown in the following reaction formula (Eq. 1), carbonylchlorohydridotris(triphenylphosphine) ruthenium(II) [RuHCl(CO)(PPh3)3] as a ruthenium source and bis[2-(diphenylphosphino)ethyl]amine as a ligand are allowed to react in toluene.

However, the production method above has a number of problems, for example, that the atom efficiency of the ruthenium source is very low (17.3 mass %) and not only 3 equivalents of difficulty-removable triphenylphosphine (PPh3) are produced as a by-product after the reaction but also the obtained Ru-MACHO is a mixture of isomers (Non-Patent Document 1).
Although Ru-MACHO can be isolated as a single isomer by washing the mixture of isomers with n-hexane and ethanol, this is associated with a problem that the yield decreases from 85% to 55% (Patent Document 1).